Energy cost of balance control during walking decreases with external stabilizer stiffness independent of walking speed
Energy cost of balance control during walking decreases with external stabilizer stiffness independent of walking speed
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DOI：
10.1016/j.jbiomech.2013.07.005
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发表时间：
2013-09-03
影响因子：
2.4
通讯作者：
van der Woude, Lucas H. V.
中科院分区：
文献类型：
--
作者：
Ijmker, Trienke;Houdijk, Han;van der Woude, Lucas H. V.
人类行走需要主动的神经肌肉控制，以确保侧向的稳定性，这会产生一定的代谢负荷。这种代谢负荷的大小以前是通过弹簧状绳索的被动外部侧向稳定来研究的。在本研究中，我们应用这一方法检验了两个假设：(1)外部稳定对能量成本的影响取决于稳定弹簧的刚度；(2)平衡控制的能量成本以及外部稳定对能量成本的影响取决于行走速度。14名健康的年轻成年人在电动跑步机上以三种不同的步行速度(70%、100%和130%的首选速度)以四种不同的弹簧刚度(760到1820N m(-1))进行稳定行走。能量成本根据每一次呼吸的氧气消耗量计算。根据运动学数据计算步态参数(步幅和步长的平均值和变异性，以及躯干加速度的变异性)。平均而言，外部稳定导致能量成本降低6%(p<；0.005)，台阶宽度(24%；p<；0.001)、台阶宽度变异性(41%；p<；0.001)和内侧躯干加速度变异性(12.5%；p<；0.005)降低。增加稳定器刚度增加了对能量成本和内侧步态参数的影响，最高达到1260N m(-1)。与预期相反，稳定的效果与步行速度无关(p=0.111)。这些结果表明，行走过程中的主动侧向稳定涉及一种与行走速度无关的能量成本。(C)2013爱思唯尔有限公司。保留所有权利。
Human walking requires active neuromuscular control to ensure stability in the lateral direction, which inflicts a certain metabolic load. The magnitude of this metabolic load has previously been investigated by means of passive external lateral stabilization via spring-like cords. In the present study, we applied this method to test two hypotheses: (1) the effect of external stabilization on energy cost depends on the stiffness of the stabilizing springs, and (2) the energy cost for balance control, and consequently the effect of external stabilization on energy cost, depends on walking speed. Fourteen healthy young adults walked on a motor driven treadmill without stabilization and with stabilization with four different spring stiffnesses (between 760 and 1820 N m(-1)) at three walking speeds (70%, 100%, and 130% of preferred speed). Energy cost was calculated from breath-by-breath oxygen consumption. Gait parameters (mean and variability of step width and stride length, and variability of trunk accelerations) were calculated from kinematic data. On average external stabilization led to a decrease in energy cost of 6% (p < 0.005) as well as a decrease in step width (24%; p < 0.001), step width variability (41%; p < 0.001) and variability of medio-lateral trunk acceleration (12.5%; p < 0.005). Increasing stabilizer stiffness increased the effects on both energy cost and medio-lateral gait parameters up to a stiffness of 1260 N m(-1). Contrary to expectations, the effect of stabilization was independent of walking speed (p = 0.111). These results show that active lateral stabilization during walking involves an energetic cost, which is independent of walking speed. (C) 2013 Elsevier Ltd. All rights reserved.